1. Field of the Invention:
This invention relates to a burner control system and in particular to a control system for the ignition and operation of an interrupted pilot burner system.
2. Brief Statement of the Prior Art:
The commonly used ignition and burner control system employs a pilot burner and main burner which are furnished fuel through controlled valves. The pilot burner is on continuously and a flame sensor is positioned in the pilot burner flame and operatively connected by the gas valve to the burner to ensure that gas is not supplied to the main and pilot burners unless a flame is present at the pilot burner. A recent U.S. Pat. No. 3,501,253, discloses a slightly more sophisticated electrical control system in which a safety switch is provided in the circuit and this safety switch responds to the current supply to the pilot burner valve so that the safety switch is in the off position unless the valve supplying gas to the pilot burner is open.
The necessity for gas conservation has prompted the design of ignition facilities for discontinuous or interrupted pilot burner systems. The various fail safe requirements of this system have triggered the development of numerous control systems which are quite complex. The use of complex systems with many distinct components, however, generates unreliability because any of the numerous components is subject to failure or maloperation.